Identity attribute definitions are custom user attributes. When you delete identity attribute definitions, you can no longer manage users based on the value of that attribute, and the attribute no longer displays in the user record.
Note: Deleting the identity attribute definition from the internal database does not delete the field in the identity source.
You can delete identity attribute definitions one at a time, or you can delete multiple identity attribute definitions at the same time.
In the Security Console, click Identity > Identity Attribute Definitions > Manage Existing.
Select the identity attribute definition that you want to delete, and click Delete.
Click Delete Identity Attribute Definition.